The characters are always alone and lonely, the leads are always lovely but bland, the settings snowy and the “secrets” nothing to summon gentleman detective Benoit Blanc over.

But holiday romances of the Hallmark school — a market Netflix has gone after with a vengeance — make for scenic cinematic comfort food at this time of year. Never spicy, rarely surprising, they’re romance novels sprinkled with tinsel and filmed in a flash, every one of them.

That includes “The Noel Diary,” a pleasant (ish) nothing from a director decades removed from his “Baby Boom/Father of the Bride/Parent Trap” heyday. Charles Shyer, who co-wrote this with a Netflix house hack (“Dangerous Lies”) blows too many of his shots at “charming,” never quite nails down the “romance” and dithers away the “mystery” in this flavorless variation on formula.

Justin Hartley, a bit player promoted to stardom via “This is Us,” is Jake Turner, our hunky, perma-stubbled star novelist pretty enough to be a romance novel cover model. He fends off flirts at his very-popular book signings with “got to get home to Ava.”

And who wouldn’t? Ava’s his beautiful Australian Shepherd, friendly and wise and almost smart enough to drive his vintage Land Rover, which is how Jake gets to and from his modernist McMansion in the Woods.

Jake’s rugged. You can tell by the stubble.

The cliched call-from-a-lawyer is how he learns his mother has died. Nothing for it but to motor out to Connecticut, tidy up her affairs and deal with her “hoarding.”

By the way, if you’ve ever dealt with a hoarder or watched TV’s “Hoarders,” let’s just say “Noel Diary” gives us a (that label again) “Hallmark version” of this illness.

Jake was estranged from his mother. Loner Jake is big on “estranged.”

But his mother’s pleasant longtime neighbor (Bonnie Bedelia, in fine form) gives him encouragement. And there’s this strange, beautiful woman staring at him from across the street. It turns out she has a connection to this house. Rachel, played by Barrett Doss of the Chadwick Boseman Supreme Court bio-pic “Marshall” and TV’s “Station 19,” is looking for a woman who used to work for Jake’s family.

That woman was their nanny. As we’ve heard this nanny reading from her diary in voice-over, we know that young woman was pregnant. And Rachel, as it turns out, is the daughter she had and gave up for adoption at 17.

No, Jake doesn’t remember the nanny. But a little sympathy and a hint of attraction means he’ll take Rachel out to dinner and send the dog to chase her car down the street when he has a belated idea about “someone who might know” as Rachel is driving away.

By the way, the smart dog chasing the Prius is the highlight of the movie.

As the snows settle in and the holidays loom, just-engaged-Rachel finds herself spending a lot of time on this quest with rich, famous and handsome Jake as we discover how many languages she speaks, tragic things about his past and whether or not she’s about to marry the right guy.

It’s so hard to approach stories like this with a fresh set of eyes and directorial enthusiasm, so it’s almost understandable that Shyer would brush past the various steps in the holiday romance recipe in a sort of “get on with it” regimen.

He blows the “meet cute,” and perfunctorily drops the elusive “diary” right into our laps because he and his fellow screenwriter can’t be bothered to make that a “Eureka” moment, or even an emotional one.

James Remar is brought in as the father Jake is also estranged from. Even though he’s built a career, from “The Warriors” and “48 Hrs.” onward, out of characters with edge and bite, there’s nothing remotely interesting about this sappy detour into syrup country.

The leads don’t have much in the way of chemistry, save that which can be almost manufactured with close-ups and sympathetic editing.

Shyer and co-writer David Golden don’t give Rachel any real romantic “choice” here — as her fiance is only glimpsed in a Facetime call. Once. All we learn from that is that she might be “settling” for a guy who “complements” her, and that she might leave one white guy for another white guy.

Shocking.

Not as shocking as noticing that fourth stringer critics from the New York Times and LA Times endorsed this room-temp treacle as something worth watching. But perhaps they’re new to the genre.

Rating: TV-PG

Cast: Justin Hartley, Barrett Doss, Bonnie Bedelia and James Remar.

Credits: Directed by Charles Shyer, scripted by David Golden and Charles Shyer. A Netflix release.

Running time: 1:39